Heating pad



Feb. 27, 1923. 1,446,991

- w. RICHMOND" HEATING PAD Filed Feb. 5, 1920 if; z

Patented Feb. 27, 1923.

I UNITED STATES PATENT OFFICE.

- WALTER RICHMOND, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE GOODWILL ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

HEATING PAD.

Appiication filed February 5, 1920. Serial No. 356,368.

To all whom it may concern:

Be it known that I, WALTER RIoHMoNn, a citizen of the United States, residing at Chicago, in the county of Cook, State of Illinois, have invented an Improvement in Heating Pads, of which the following is a specification.

This invention relates to electro therapeutic apparatus and particularly to a heating pad, useful for treatment of mastoid and sinus condition and other conditionsrequiring the local application for considerable periods of a uniform heat, distributed only over a substantially small area.

It is an object of the invention to produce a device of the character described, which is simple and efficient in construction and operation and readily applicable to the ordinary commercial lighting circuit.

It is another object of the invention to produce a heating pad which although involving a relatively small amount of resistance wire, may nevertheless be utilized in the ordinary lighting circuit without being subject to excessive potential between the parts of the pad.

In the drawings which present an illustrative embodiment of the invention, which latter is not limited to the specific features shown in the drawings:

Fig. 1 is a plan view of the complete upparatus;

Fig. 2 is a digrammatic illustration of the wiring system therefor.

In the drawings is shown a heating pad 1, preferably made up of coils of soft braided material wound with resistance wire, and provided'with a small thermostat box 2, adjustable to control the temperature of the pad. The specific interior construction of the thermostat may be as illustrated in the Richmond Patent No. 869,460, October 29, 1907.

The pad here shown is a small pad designed for local application. It is preferably made of the shape shown in the drawings, somewhat crescent formed in contour and with rounded ends as shown, this form being specially useful as peculiarly ada ted to various parts of the head. Thus the orm shown will fit snugly and comfortable behind the ear to serve in treating mastoid conditions. It will also fit over a sinus on the brow, completely covering the region to be treated without interfering with the vision, and is Welladapted for many other local applications, being accordingly limited in its size.

- In order to make the application of the pad convenient, I provide cloth straps 3, one of which is equipped with a buckle 4, as shown, whereby the pad may be strapped on the head in the desired position.

The wires 5 from the pad contain a pullapart connection 6--6 and are of considerable length as indicated by the coils in Fig. 1. These Wires lead to the attachment 7, provided with sockets for, the reception of the lamp 8 and the smaller lamp 9. The attachment 7 is adapted to fit into an ordinary electric lighting socket; for this purpose being provided with the customary threaded plug 10.

I will now describe the circuit arrangement for the apparatus, as used in service, reference bein had to the diagrammatical illustration of Tig. 2. Thus I provide a lead wire 11, leading from one poletothe thermostat points 12, the current passing through these points and through the coils 13 of the heating pad, back through the lead wire 14.

In operation it will be understood that the thermostat points 12 may make and break the circuit through the pad in accordance with the temperature thereof, opening as soon as the temperature of the pad reaches a predetermined adjustable value and closing when the pad falls below that temperature. In a small pad such as applicable for limited and local treatment of mastoid conditions,

etc., the resistance of the pad itself may not be sufiicient to reduce the ordinary light current sufficiently; so that without some special provision an excessive potential would be developed between the heating coils. Furthermore and for the same reason excessive and very undesirable sparking is apt to occur at the thermostat points.

The provisions illustrated in Fig. 2 serve completely to avoid both of these difficulties and to produce at the same time other advantages' To provide for these contingencies, I provide a pair of lamps. A relatively .large lamp 8 is interposed in the lead wire 14. Bridged across the thermostat and the pad (diagrammatically illustrated by reference characters 12 and 13 in Fig. 2) I provide the conductor IG-passing through the rela tively small lamp 9 and connected to the conductors 11 and 14.

Thus it will be observed that during the time the thermostat points 12 are closed the current passes through the small lamp 9 and the pad coils 13, arranged in parallel, and then through the large lamp 8 arranged in series with the small lamp and pad coil. The resistance of the large lamp, as well as the small lamp and coil (in parallel) sufficiently reduce the current going through the coil 13, so as to make the pad perfectly safe to be used upon the ordinary high tension commercial lighting circuit.

The small and large lamps 8 and 9 are so arranged and coordinated with the pad and with each other, that the current as presented to the large lamp 8 after having passed through the small lamp 9 and the pad coil 13 (arranged in parallel) is sufiicient to cause the large lamp to glow; so that during the time the current is passing through the pad the large lamp lows. On the other hand when the thermostat points 12 are open the two lamps 8 and 9 are directly in series and the resistance of the small lamp issufiicient to extinguish the large lamp while the small lamp is itself illuminated. Thus in operation the large and small lamps will flash alternately, indicating the regular passage of current for small periods through th pad. This is an advantageous result in the therapeutic use of the pad; as it indicates to the patient and attendant that the pad is working regularly and correctly. It is impossible for any substantial departure from the correct and normal operation of the pad to occur without changing the. regular dash of the li hts, and extremely advantageous result w ere the pad is used in serious mastoid or sinus conditions Where the most definite certain of correct. operation is extremely important.

For illustrative purposes and or the purpose of utilizing the padon an 110 volt lighting circuit, ll employ a pad which consumes approximately 10 watts and can be adjusted through the thermostat to operate at any temperature between 109 and 180. For the small lamp ll utilize a 110 volt 10 watt lamp; and for the large lamp 1 utilize a 110 volt watt lamp. This combination ll have found produces most effective and certain results.

Having now described my invention, ll claim:

1. In apparatus of the class described, an electric heating pad, a make and break d vice associated therea. 1th, a circuit in which said pad and make and break device-are located, a resistance in the circuit, a smaller resistance bridged across the circuit.

2. In apparatus of the class described, an electrical apparatus, a circuit closer therefor,

a circuit in which said apparatus and closer are located, a resistance in said circuit, adapted to reduce the potential in the apparatus, a bridge across said circuit, a resistance in said bridge higher than the resaid heating pad, a lamp in said circuit, a.

smaller lamp bridged across said therm0- stat, whereby said lamps will reduce the potential of the pad and flash alte nately to indicate the periods of rest. and passage of current through said pad.

5. A medical electrical appliance adapted to be connected to a commercial lighting circuit, comprising a heating pad of small size adapted to local and limited applications such as upon the ear, sinus, etc., and comprising a series of coils of resistance wire, a thermostat in circuit with said resistance wire and adapted to interrupt and restore the circuit thereto; and means to reduce the current of the lighting circuit to make the same available for the operation of the pad, comprising a lamp in the circuit, a smaller lamp bridged across the thermostat, whereby when the thermostat is closed the total resistance of the pad and the smaller lamp will reduce the current so as to be safe for the former and light the large lamp; when the thermostat is closed the small lamp alone will glow.

6. An electro-medical appliance comprising in combination a heating pad, a thermostat controlling the flow of current through said pad, a circuit through the pad and thermostat and means for introducing said circuit into a commercial lighting circuit, a lamp in said first circuit, a lamp bridging said thermostat and pad; said two lamps being constructed and arranged so that the resistance of the first is such as to cause the second to glow and to prevent excessive current in the pad while the thermostat is closed and the pad and second'lamp are in parallel; while the resistance of the second lamp is lower than that at the spark gap in .the'thermostat but greater than that of the pad, and suflicient to extinguish the first lamp, when the thermostat circuit'is open and the two lamps are in series.

7 lln apparatus of the class. described, an electrically operated device, a circuit breaker, associated therewith, a pair of lamps, one thereof arranged in the circuit and inseries iso with the other and with the device, the other in parallel with the device and in series with the first.

8. In apparatus of the class described an electrically operated device, a circuit breaker, associated therewith, a pair of lamps, one thereof arranged in the circuit and in series with the other and with the device; the

, other in parallel with the device and in" series with the first, the resistance of the second being larger than that of the first.

9. In apparatus of the class described an WALTER RICHMOND. 

